Blood pressure is often measured as biological information indicating a person's state of health. One proposed method of measuring blood pressure is a method of measuring the pulse wave of a subject and calculating blood pressure on the basis of the measured pulse wave. In Patent Document 1, the applicant proposed a noninvasive blood pressure measurement method for estimating the blood pressure of a subject from the time difference (propagation velocity) between pulse waves measured by fiber Bragg grating sensors (referred to below as “FBG sensors”) attached to multiple locations on the subject.
Patent Document 2 proposes a method of detecting a parameter such as the time taken by an arterial waveform to reach a maximum value from a minimum value, on the basis of the arterial waveform, and detecting a highest blood pressure and a lowest blood pressure. Patent Document 3 proposes a method of calculating an acceleration pulse wave from a measured volume pulse wave, and determining the highest blood pressure and lowest blood pressure of the subject from the inflection point of the acceleration pulse wave.